I created a aggregate var by the name ^TaxonomyList as a result of a list aggregation using GroupBy, and this fails, as my taxonomy list is too large. What is the maximum size that you support for a agg var?

Xcalar allows you to explore it's data and features flexibly. This would be an interesting exercise to figure out. It would not make sense to work with a threshold and statically encode it in any future designs. What you can do, is to attempt to create

> listagg

for an aggregate, and use Strings, so you can expand the size of the resultant aggregate variable. Testing limits then becomes a very easy problem.